Help my Husband stay in Australia

My husband Dan has been living in Australia for 10 years now. We had applied for partner visa back in 2009 and got knocked back 2016 due to 1 piece of paper being only a few weeks late for the deadline due to lack of orginisation of immigration departments. We are now at risk of loosing him as they want him to go back home to Ireland & apply all over again costing another $7000. He has no criminal record & far from being a Terrorist. We are a very happy married couple for 9yrs this October. We have 3 beautiful children - 1 boy 6yrs old with Global developmental delay,  2 girls 4 & 3yrs old, our 4yr old daughter has Autism and needs her Daddy very much at this crutial time in their life providing structure & routine. We may loose our house aswell as I will not be able to work to pay our mortgage. We need to keep a roof over our heads and to get more Legal support. PLEASE HELP US KEEP OUR LITTLE FAMILY TOGETHER...!!